As I sat in my sparse office one afternoon before Thanksgiving, a knock rapped against my door. I expected it to be a student asking for an extension on a paper, or a faculty member asking me to take another class next semester.

I leaped up from the desk and rushed into his arms, the first time I’d seen him in years. Then I emailed my final class of the day and wished them a happy Thanksgiving, and let them know that they could go home early.

“Gordon, I can’t believe you’re here. What are you doing?”

“Just passing through town, and figured I’d stop in to say hello.” I looked at him for a minute. His hair was cut shorter, but those cra...